Mary Elizabeth Bowser and Elizabeth Van Lew, a former slave and a wealthy white woman in Richmond, Virginia, might seem unlikely members of a successful espionage ring. Thanks to Hollywood, the typical images surrounding spies include scantily clad women, technological gadgets, and Pierce Brosnan—but this equation would hardly have gone unnoticed during the Civil War. Bowser and Van Lew used society's assumptions about them to their advantage, passing key information along to the Union Army and contributing to the demise of the Confederate States.

Imagine, if you will, that you are living in Missouri at the end of the Civil War (1864 or thereabouts). Imagine also that you are a woman without a ton of moneymaking options who is in need of a job ASAP. Oh, and you are also a recently freed slave living in a place and time where people are still getting used to the idea that you aren't a piece of property. (And we thought it was tough to find a job in this economy.) What on earth will you do to support yourself?

Well, if you are a feisty entrepeneuse with a working knowledge of military life like Ms. Cathay Williams, what you will do is dress in drag and join the U.S. Army.

"I am naturally fond of adventure, a little ambitious, and a good deal romantic-but patriotism was the true secret of my success."

Sarah Emma Edmonds, one of only about 400 women known to have served in the military during the U.S. Civil War, was not even an American—though she risked life and limb in the name of "patriotism" to serve the Union cause for nearly two years as a soldier, nurse and spy.